CN116472496A - Laser interference lithography apparatus and method - Google Patents
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- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
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- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
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Abstract
Description
本发明涉及光刻领域。更具体地,本发明涉及激光干涉光刻设备和方法。The present invention relates to the field of lithography. More specifically, the present invention relates to laser interference lithography apparatus and methods.
干涉光刻是一种在覆盖大面积的阵列亚微米结构进行构图的技术。将两束或多束相干光波的干涉记录到光致抗蚀剂上来产生多种规则周期性图案的结构,包括光栅、孔洞、柱、锥体和格子。当将相干激光束分束为两个或多个束、然后在一定的区域组合并且重叠时,将形成光栅或光点的规则光强度图案。通过这些光强度图案对光致抗蚀剂材料进行曝光,并且在显影之后记录干涉图案。这种光刻技术允许使用较短的曝光时间实现大面积衬底的无掩模构图。干涉光刻可以高生产率和低成本地在较大面积上产生周期性纳米结构,因此在新兴的能源、感测、发光和其他应用中起到重要的作用。Interference lithography is a technique for patterning submicron structures in arrays covering large areas. The interference of two or more beams of coherent light waves is recorded onto photoresist to produce a variety of regular periodic patterns of structures, including gratings, holes, pillars, cones, and lattices. When a coherent laser beam is split into two or more beams which are then combined and overlapped in a certain area, a regular light intensity pattern of gratings or spots is formed. The photoresist material is exposed through these light intensity patterns and after development an interference pattern is recorded. This lithographic technique allows maskless patterning of large area substrates using shorter exposure times. Interference lithography can produce periodic nanostructures over large areas with high productivity and low cost, thus playing an important role in emerging energy, sensing, light emitting and other applications.
通常,干涉光刻可以通过两种不同的方案产生周期性图案,即,劳埃德(Lloyd)反射镜结构和双束全息成像结构。然而,在采用干涉光刻来制备周期性纳米图案时,往往存在由于所用光源的曝光光场不均匀而导致经干涉图案曝光后的光刻胶图案占空比不均匀的问题,从而降低了产品的工艺精度。此外,很多应用中需要获得随位置变化的占空比分布的图案,例如,具有占空比线性变化的图案等。这样的需求通常难以通过干涉光刻的曝光光场获得。因此,对于高生产率且低成本的干涉光刻设备而言,难以满足这样的需求。In general, interference lithography can generate periodic patterns through two different schemes, namely, Lloyd mirror structures and dual-beam holographic imaging structures. However, when interferometric lithography is used to prepare periodic nanopatterns, there is often the problem that the duty ratio of the photoresist pattern exposed by the interference pattern is not uniform due to the inhomogeneous exposure light field of the light source used, thereby reducing the process accuracy of the product. In addition, in many applications, it is necessary to obtain a pattern of duty cycle distribution that varies with position, for example, a pattern with a linear change in duty cycle, etc. Such requirements are usually difficult to obtain through the exposure light field of interference lithography. Therefore, it is difficult to meet such demands for a high-productivity and low-cost interference lithography apparatus.
因此,需要一种能够提供期望光刻图案的激光干涉光刻设备和方法,其中所述激光干涉光刻设备和方法能够以较高的精度提供期望的光刻图案,而不会显著增加设备的复杂程度和制造成本。Therefore, there is a need for a laser interference lithography apparatus and method capable of providing a desired lithography pattern with high precision without significantly increasing the complexity and manufacturing cost of the apparatus.
发明内容Contents of the invention
本公开的目的在于至少解决上述问题中的一部分或全部。The purpose of the present disclosure is to solve at least some or all of the above-mentioned problems.
本公开的一个方面提供了一种激光干涉光刻设备,包括:双光束或多光束激光干涉光刻设备,被配置为对涂覆有光刻胶的晶片进行干涉曝光;泛光光源,具有可被图案化的光场分布,并被配置为对经干涉曝光的晶片进行图案化泛曝光;以及控制器,被配置为:确定在经干涉曝光的晶片中的第一光场分布;基于所述第一光场分布、预期的图案分布和所述泛光光源的参数,确定所述泛光光源的光场分布,作为第二光场分布;以及基于所述第二光场分布,对所述泛光光源的光场分布进行图案化,并控制具有经图案化的光场分布的所述泛光光源对经干涉曝光的晶片进行图案化泛曝光,从而在经泛曝光的晶片中形成所述预期的图案分布。One aspect of the present disclosure provides a laser interference lithography apparatus, comprising: a two-beam or multi-beam laser interference lithography apparatus configured to perform interference exposure on a photoresist-coated wafer; a flood light source having a light field distribution that can be patterned and configured to perform patterned flood exposure on the interference exposed wafer; and a controller configured to: determine a first light field distribution in the interference exposed wafer; determine the light field distribution of the flood light source based on the first light field distribution, an expected pattern distribution, and parameters of the flood light source , as a second light field distribution; and based on the second light field distribution, patterning the light field distribution of the flood light source, and controlling the flood light source with the patterned light field distribution to perform patterned flood exposure on the interference-exposed wafer, thereby forming the desired pattern distribution in the flood-exposed wafer.
在一个示例中,所述泛光光源还包括离焦模块,被配置为使由所述泛光光源发出的光离焦,以形成经泛化的模糊光斑。In one example, the flood light source further includes a defocusing module configured to defocus the light emitted by the flood light source to form a generalized blurred light spot.
在另一示例中,所述泛光光源还包括电机,被配置为通过使所述泛光光源小幅移动,以形成经泛化的模糊光斑。In another example, the flood light source further includes a motor configured to form a generalized blurred light spot by making the flood light source move slightly.
在另一示例中,所述泛光光源还可以包括光场图案化模块,其中所述控制器还被配置为经由所述光场图案化模块对所述泛光光源的光场分布进行图案化,以具有所述第二光场分布。In another example, the flood light source may further include a light field patterning module, wherein the controller is further configured to pattern the light field distribution of the flood light source to have the second light field distribution via the light field patterning module.
在另一实施例中,所述激光干涉光刻设备还可以包括显影单元,被配置为对经过泛曝光的晶片进行显影。In another embodiment, the laser interference lithography apparatus may further include a developing unit configured to develop the flood-exposed wafer.
在另一实施例中,使用来自UV投影仪的灰度图来实现图案化的泛光光源,其中所述灰度图中的不同灰度值表示不同光强。In another embodiment, a patterned flood light source is realized using a grayscale map from a UV projector, wherein different grayscale values in the grayscale map represent different light intensities.
在另一实施例中,所述第一光场分布是理想干涉图案,且所述第二光场分布是均匀分布。In another embodiment, the first light field distribution is an ideal interference pattern and the second light field distribution is a uniform distribution.
在另一实施例中,所述第一光场分布是理想干涉图案,且所述第二光场分布是阶梯状分布。In another embodiment, the first light field distribution is an ideal interference pattern, and the second light field distribution is a stepped distribution.
本公开的另一方面提供了一种激光干涉光刻方法,可以包括:对涂覆有光刻胶的晶片执行干涉曝光;以及对经干涉曝光的晶片执行图案化泛曝光,其中执行图案化泛曝光包括:确定在所述经干涉曝光的 晶片中的第一光场分布;基于所述第一光场分布、预期的图案分布和用于所述图案化泛曝光的泛光光源的参数,确定所述泛光光源的光场分布,作为第二光场分布;以及基于所述第二光场分布,对所述泛光光源的光场分布进行图案化,并控制具有经图案化的光场分布的所述泛光光源对经干涉曝光的晶片进行图案化泛曝光,从而在经泛曝光的晶片中形成所述预期的图案分布。Another aspect of the present disclosure provides a method of laser interference lithography, which may include: performing interference exposure on a photoresist-coated wafer; and performing patterned flood exposure on the interference-exposed wafer, wherein performing patterned flood exposure includes: determining a first light field distribution in the interference-exposed wafer; The field distribution is patterned, and the flood light source having the patterned light field distribution is controlled to perform a patterned flood exposure on the interference exposed wafer, thereby forming the desired pattern distribution in the flood exposed wafer.
在一个示例中,所述激光干涉光刻方法可以附加地包括:对经泛曝光的晶片执行显影处理。In one example, the laser interference lithography method may additionally include performing a development process on the flood exposed wafer.
在另一示例中,确定所述第一光场分布包括:对经干涉曝光的样品进行显影;通过扫描电子显微镜对经显影的晶片的轮廓进行检测;以及基于检测到的轮廓,确定在经干涉曝光的晶片中的第一光场分布。In another example, determining the first optical field distribution includes: developing the interference-exposed sample; inspecting a profile of the developed wafer with a scanning electron microscope; and determining the first optical field distribution in the interference-exposed wafer based on the detected profile.
在另一示例中,确定所述第二光场分布可以包括:响应于确定所述预期的图案分布为具有均匀占空比的周期性图案,确定在所述第一光场分布较小的位置处施加较高的泛曝光剂量,且在所述第一光场分布较大的位置处施加较低的泛曝光剂量。In another example, determining the second light field distribution may include: in response to determining that the expected pattern distribution is a periodic pattern with a uniform duty cycle, determining to apply a higher flood exposure dose at locations where the first light field distribution is smaller, and applying a lower flood exposure dose at locations where the first light field distribution is larger.
在另一示例中,确定所述第二光场分布可以包括:确定所述第二光场分布包括:响应于确定所述预期的图案分布是具有空间调制的占空比的图案分布,确定所述第二光场分布,使得经泛曝光的晶片中形成所述具有空间调制的占空比的图案分布。In another example, determining the second light field distribution may include: determining the second light field distribution includes: in response to determining that the expected pattern distribution is a pattern distribution with a spatially modulated duty cycle, determining the second light field distribution such that the pattern distribution with a spatially modulated duty cycle is formed in the flood exposed wafer.
在另一实施例中,使用来自UV投影仪的灰度图来实现图案化的泛光光源,其中所述灰度图中的不同灰度值表示不同光强。In another embodiment, a patterned flood light source is realized using a grayscale map from a UV projector, wherein different grayscale values in the grayscale map represent different light intensities.
在另一实施例中,所述第一光场分布是理想干涉图案,且所述第二光场分布是均匀分布。In another embodiment, the first light field distribution is an ideal interference pattern and the second light field distribution is a uniform distribution.
在另一实施例中,所述第一光场分布是理想干涉图案,且所述第二光场分布是阶梯状分布。In another embodiment, the first light field distribution is an ideal interference pattern, and the second light field distribution is a stepped distribution.
图1示出了根据本公开示例实施例的光纤型双光束激光干涉光刻设备的架构;FIG. 1 shows the architecture of a fiber-type dual-beam laser interference lithography apparatus according to an exemplary embodiment of the present disclosure;
图2A至图2C示出了根据本公开示例实施例的激光干涉光刻设备 的构思原理图;2A to 2C show conceptual schematic diagrams of a laser interference lithography apparatus according to an exemplary embodiment of the present disclosure;
图3示出了根据本公开示例实施例的激光干涉光刻设备的架构图;FIG. 3 shows an architecture diagram of a laser interference lithography apparatus according to an exemplary embodiment of the present disclosure;
图4示出了根据本公开示例实施例的激光干涉光刻方法的流程图;FIG. 4 shows a flowchart of a laser interference lithography method according to an exemplary embodiment of the present disclosure;
图5示出了根据本公开示例实施例的泛曝光工艺的流程图;以及FIG. 5 shows a flowchart of a flood exposure process according to an exemplary embodiment of the present disclosure; and
图6示出了利用本公开示例实施例的激光干涉光刻设备和方法形成的周期例如为1μm的栅状结构。FIG. 6 shows a grid-like structure with a period of, for example, 1 μm formed using the laser interference lithography apparatus and method of an exemplary embodiment of the present disclosure.
图7示出了利用根据本公开示例实施例的激光干涉光刻设备和方法在3英寸样品上制造具有空间调制的占空比的图案的样品图。FIG. 7 shows a sample diagram of fabricating a pattern with a spatially modulated duty cycle on a 3-inch sample using a laser interference lithography apparatus and method according to an example embodiment of the present disclosure.
图8示出了使用根据本公开示例实施例所述的方法和装置在大尺寸晶片上获得具有均匀线宽的栅状结构的示例。FIG. 8 shows an example of obtaining a grid-like structure with a uniform line width on a large-sized wafer using the method and apparatus according to example embodiments of the present disclosure.
图9示出了通过使用根据本公开示例实施例的方法和装置来对二维纳米结构的填充率进行空间调制的示例。FIG. 9 shows an example of spatially modulating the fill rate of a two-dimensional nanostructure by using the method and apparatus according to example embodiments of the present disclosure.
以下,将参照附图来描述本公开的实施例。但是应该理解,这些描述只是示例性的,而并非要限制本公开的范围。在下面的详细描述中,为便于解释,阐述了许多具体的细节以提供对本公开实施例的全面理解。然而,明显地,一个或多个实施例在没有这些具体细节的情况下也可以被实施。此外,在以下说明中,省略了对公知结构和技术的描述,以避免不必要地混淆本公开的概念。Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. It should be understood, however, that these descriptions are exemplary only, and are not intended to limit the scope of the present disclosure. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concept of the present disclosure.
在此使用的术语仅仅是为了描述具体实施例,而并非意在限制本公开。在此使用的术语“包括”、“包含”等表明了所述特征、步骤、操作和/或部件的存在,但是并不排除存在或添加一个或多个其他特征、步骤、操作或部件。The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting of the present disclosure. The terms "comprising", "comprising", etc. used herein indicate the presence of stated features, steps, operations and/or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.
在此使用的所有术语(包括技术和科学术语)具有本领域技术人员通常所理解的含义,除非另外定义。应注意,这里使用的术语应解释为具有与本说明书的上下文相一致的含义,而不应以理想化或过于刻板的方式来解释。All terms (including technical and scientific terms) used herein have the meaning commonly understood by one of ordinary skill in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted to have a meaning consistent with the context of this specification, and not be interpreted in an idealized or overly rigid manner.
在使用类似于“使A、B和C等中至少一个”这样的表述的情况下,一般来说应该按照本领域技术人员通常理解该表述的含义来予以解释 (例如,“具有A、B和C中至少一个的系统”应包括但不限于单独具有A、单独具有B、单独具有C、具有A和B、具有A和C、具有B和C、和/或具有A、B、C的系统等)。在使用类似于“系、B或C等中至少一个”这样的表述的情况下,一般来说应该按照本领域技术人员通常理解该表述的含义来予以解释(例如,“具有A、B或C中至少一个的系统”应包括但不限于单独具有A、单独具有B、单独具有C、具有A和B、具有A和C、具有B和C、和/或具有A、B、C的系统等)。Where an expression similar to "at least one of A, B, and C, etc." is used, it should generally be interpreted according to the meaning that those skilled in the art usually understand the expression (for example, "a system having at least one of A, B, and C" shall include, but not limited to, a system having A alone, B alone, C alone, A and B, A and C, B and C, and/or A, B, C, etc.). Where an expression similar to "at least one of the system, B, or C, etc." is used, it should generally be interpreted according to the meaning generally understood by those skilled in the art (for example, "a system having at least one of A, B, or C" shall include, but not limited to, a system having A alone, B alone, C alone, A and B, A and C, B and C, and/or A, B, C, etc.).
附图中,相同或相似的附图标记用于表示相同或相似的结构。In the drawings, the same or similar reference numerals are used to denote the same or similar structures.
图1示出了根据本公开示例实施例的光纤型双光束激光干涉光刻设备的架构。FIG. 1 shows the architecture of a fiber-type two-beam laser interference lithography apparatus according to an exemplary embodiment of the present disclosure.
具体地,根据本公开示例实施例的光纤型双光束激光干涉光刻设备包括激光源110和光纤分束器120。激光源110可以是单频紫外激光器,其输出高相干性的单频紫外光。例如,激光源110的波长可以是266nm、351nm、355nm、360nm或其他紫外或近紫外波长。高相干性的单频紫外光通过单模保偏光纤(PMF)输出至光纤分束器120。在优选实施例中,光纤分束器120可以同样是偏振保持的,并用于将输入的高相干性的单频紫外光分为至少两个子激光束。所述至少两个子光束形成干涉图案,从而对位于操作台上的且被诸如夹持器夹持的晶片进行干涉曝光。Specifically, a fiber-type dual-beam laser interference lithography apparatus according to an exemplary embodiment of the present disclosure includes a laser source 110 and a fiber beam splitter 120 . The laser source 110 may be a single-frequency ultraviolet laser, which outputs highly coherent single-frequency ultraviolet light. For example, the wavelength of the laser source 110 may be 266 nm, 351 nm, 355 nm, 360 nm or other ultraviolet or near ultraviolet wavelengths. The highly coherent single-frequency ultraviolet light is output to the fiber splitter 120 through a single-mode polarization-maintaining fiber (PMF). In a preferred embodiment, the fiber beam splitter 120 can also be polarization-maintaining, and is used to split the input high-coherence single-frequency ultraviolet light into at least two sub-laser beams. The at least two sub-beams form an interference pattern to perform interference exposure on a wafer positioned on a stage and held by, for example, a gripper.
此外,该光纤型双光束激光干涉光刻设备还可以附加地包括控制器140、光电探测器150、致动器130和片状分束器。如图1所示,例如压电陶瓷的致动器130可以位于光纤分束器120的至少一个分支上,使得控制器140能够基于光电探测器150对干涉图案的检测,来控制该致动器130改变其所在分支上的子光束的相位以改变干涉图案。In addition, the fiber-optic double-beam laser interference lithography apparatus may additionally include a controller 140, a photodetector 150, an actuator 130, and a sheet beam splitter. As shown in FIG. 1 , an actuator 130 such as a piezoelectric ceramic may be located on at least one branch of the optical fiber beam splitter 120, so that the controller 140 can control the actuator 130 to change the phase of the sub-beam on the branch where it is located to change the interference pattern based on the detection of the interference pattern by the photodetector 150.
以下将以图1所示的光纤型双光束激光干涉光刻设备作为双光束或多光束激光干涉光刻设备的例示,然而,应清楚的是本发明构思不仅适用于如图1所示的光纤型双光束激光干涉光刻设备,而且还适应于劳埃德反射镜结构及其他双光束或多光束激光干涉光刻设备。In the following, the fiber-optic double-beam laser interference lithography apparatus shown in FIG. 1 will be used as an example of a double-beam or multi-beam laser interference lithography apparatus. However, it should be clear that the concept of the present invention is not only applicable to the fiber-optic double-beam laser interference lithography apparatus shown in FIG.
图2A至图2C示出了根据本公开示例实施例的激光干涉光刻设备的构思原理图。图2A至图2C以采用正性光刻胶的情况为例示出了在 理想干涉图案、未经泛曝光处理的实际干涉图案以及经过泛曝光补偿的补偿干涉图案下产生的周期性图案的示意图。2A to 2C illustrate conceptual schematic diagrams of a laser interference lithography apparatus according to an exemplary embodiment of the present disclosure. 2A to 2C take the case of positive photoresist as an example to show schematic diagrams of the periodic patterns generated under the ideal interference pattern, the actual interference pattern without flood exposure treatment, and the compensated interference pattern after flood exposure compensation.
如图2A所示,在理想情况下,干涉图案具有完美的周期性。此时,由于采用正性光刻胶,所以曝光剂量在光分布高于光刻胶损伤阈值剂量的位置处,光刻胶被洗掉。这样,就可以构造具有完美周期性的图案。然而,由于曝光光场往往不均匀(通常为高斯光束),因此,会造成干涉图案曝光后的光刻胶图案占空比不均匀,如图2B所示。As shown in Figure 2A, under ideal conditions, the interference pattern has perfect periodicity. At this time, since the positive photoresist is used, the exposure dose is at a position where the light distribution is higher than the photoresist damage threshold dose, and the photoresist is washed away. In this way, patterns with perfect periodicity can be constructed. However, since the exposure light field is often non-uniform (usually a Gaussian beam), the duty cycle of the photoresist pattern after the interference pattern exposure will be non-uniform, as shown in FIG. 2B .
为了克服上述问题,本申请提出在干涉曝光后采用图案化泛曝光来补偿由于干涉曝光的光场不均匀而导致的制造器件的工艺误差,例如,周期型器件的占空比不均匀的问题。具体地,可以在经过图2B所示的干涉图案的曝光之后,采用发射波长在光刻胶的敏感波长范围内的泛光光源进行图案化泛曝光(patterned flood exposure),或简称为泛曝光,以补偿干涉曝光的光场不均匀。具体地,可以设计泛光光源的光场分布,使得在经泛曝光的晶片中的累积曝光剂量分布能够展现具有均匀的占空比的图案,如图2C所示。或者,更进一步,设计泛光光源的光场分布,使得在经泛曝光的晶片中的累积曝光剂量分布能够展现预期的光场分布,从而得到预期的光刻图案。也就是说,通过采用图案化泛曝光来对干涉曝光进行补偿的方法,不仅可以获得占空比均匀的周期性结构,也可以获得经空间调制的占空比分布,例如,获得占空比在一定范围内线性变化、占空比周期变化、占空比成径向变化,甚至任何给定图案等。这种图案化二次曝光可以通过紫外线投射曝光、带掩模的紫外线光刻和定向激光写入来实现。还应注意的是,尽管图2A至图2C以正性光刻胶为例示出了本申请的发明构思,然而本申请不限于此,本申请同样可以应用于负性光刻胶、反转胶等多种类型的光刻胶。In order to overcome the above problems, the present application proposes to use patterned flood exposure after interference exposure to compensate the process error of manufacturing devices caused by the uneven light field of interference exposure, for example, the problem of uneven duty cycle of periodic devices. Specifically, after the exposure of the interference pattern shown in FIG. 2B , a flood light source whose emission wavelength is within the sensitive wavelength range of the photoresist can be used to perform patterned flood exposure (patterned flood exposure), or simply referred to as flood exposure, to compensate for the uneven light field of the interference exposure. Specifically, the light field distribution of the flood light source can be designed such that the cumulative exposure dose distribution in the flood exposed wafer exhibits a pattern with a uniform duty cycle, as shown in FIG. 2C . Or, further, the light field distribution of the flood light source is designed so that the cumulative exposure dose distribution in the flood-exposed wafer can exhibit the expected light field distribution, so as to obtain the expected photolithography pattern. That is to say, by using patterned flood exposure to compensate for interference exposure, not only a periodic structure with uniform duty ratio can be obtained, but also a spatially modulated duty ratio distribution can be obtained. This patterned secondary exposure can be achieved by UV projection exposure, masked UV lithography, and directional laser writing. It should also be noted that although FIG. 2A to FIG. 2C illustrate the inventive concept of the present application by taking positive photoresist as an example, the present application is not limited thereto, and the present application can also be applied to various types of photoresist such as negative photoresist and reverse resist.
以下参考图3至图5描述根据本公开示例实施例的激光干涉光刻设备和方法。A laser interference lithography apparatus and method according to example embodiments of the present disclosure are described below with reference to FIGS. 3 to 5 .
具体地,图3示出了根据本公开示例实施例的激光干涉光刻设备的架构图。如图3所示,根据本公开示例实施例的激光干涉光刻设备包括双光束或多光束激光干涉光刻设备310、泛光光源320和控制器 330。具体地,双光束或多光束激光干涉光刻设备310用于对涂覆有光刻胶的样品晶片进行激光干涉曝光。控制器330可以确定在经干涉曝光的晶片中的第一光场分布;基于所述第一光场分布、预期的图案分布和泛光光源320的参数(例如,波长、功率等),确定所述泛光光源的光场分布,作为第二光场分布;以及基于所述第二光场分布,对所述泛光光源的光场分布进行图案化,并控制具有经图案化的光场分布的所述泛光光源对经干涉曝光的晶片进行图案化泛曝光,从而在经泛曝光的晶片中形成所述预期的图案分布。Specifically, FIG. 3 shows an architecture diagram of a laser interference lithography apparatus according to an exemplary embodiment of the present disclosure. As shown in FIG. 3 , a laser interference lithography apparatus according to an exemplary embodiment of the present disclosure includes a double-beam or multi-beam laser interference lithography apparatus 310 , a flood light source 320 and a controller 330 . Specifically, the dual-beam or multi-beam laser interference lithography apparatus 310 is used to perform laser interference exposure on a sample wafer coated with photoresist. The controller 330 may determine a first light field distribution in the interference-exposed wafer; determine a light field distribution of the flood light source as a second light field distribution based on the first light field distribution, the expected pattern distribution, and parameters of the flood light source 320 (e.g., wavelength, power, etc.); The expected pattern distribution.
双光束或多光束激光干涉光刻设备310例如可以采用如图1所示的光纤型双光束或多光束激光干涉光刻设备来实现,其可以被配置为对涂覆有光刻胶的晶片进行干涉曝光。例如,所述双光束或多光束激光干涉光刻设备310可以包括:激光光源,被配置为发射高相干性的紫外/近紫外单频光(例如,波长为405nm);输入耦合光纤,配置为将来自激光光源的相干激光光束耦合至光纤分束器;光纤分束器,配置为将来自输入耦合光纤的相干激光分束为至少两个子激光束,并且通过两个或多个输出耦合光纤输出所述子激光束,从而对涂覆有光刻胶的晶片进行干涉曝光。The double-beam or multi-beam laser interference lithography apparatus 310 can be implemented, for example, by using a fiber-type double-beam or multi-beam laser interference lithography apparatus as shown in FIG. 1 , which can be configured to perform interference exposure on a wafer coated with photoresist. For example, the two-beam or multi-beam laser interference lithography apparatus 310 may include: a laser light source configured to emit highly coherent ultraviolet/near-ultraviolet single-frequency light (for example, a wavelength of 405 nm); an input coupling fiber configured to couple the coherent laser beam from the laser light source to a fiber beam splitter; a fiber beam splitter configured to split the coherent laser beam from the input coupling fiber into at least two sub-laser beams, and output the sub-laser beams through two or more output coupling fibers, so that the wafer coated with photoresist Perform interference exposure.
泛光光源320可以具有可被图案化的光场分布,并被配置为对经干涉曝光的晶片进行图案化泛曝光,即,利用经图案化的泛化光斑对晶片进行曝光。具体地,泛光光源320可以包括离焦模块,其中所述离焦模块可以由离焦光学器件来实现,其被配置为使由所述泛光光源发出的光离焦(out of focus),以形成经泛化的模糊光斑。或者,泛光光源320还可以备选地包括电机,该电机被配置为使所述泛光光源小幅移动,以形成经泛化的模糊光斑。此外,泛光光源320通常还可以包含例如空间光调制器的光场图案化模块,以用于形成图案化的灰度光场分布。由于数字灰度图上的不同灰度值代表投影图案上不同的光强,因此可以根据灰度图执行图案化泛曝光。此外,泛光光源320可以与双光束或多光束激光干涉光刻设备310所包括的激光光源具有相同或不同的波长,只要二者均是在光刻胶的敏感波长范围内即可。在示例中,可以选用405nm或365nm作为泛光光源的波长。The flood light source 320 may have a patternable light field distribution and is configured to perform patterned flood exposure on an interference exposed wafer, ie, to expose the wafer with a patterned flood spot. Specifically, the flood light source 320 may include a defocus module, wherein the defocus module may be implemented by a defocus optical device configured to defocus the light emitted by the flood light source to form a generalized blurred spot. Or, the flood light source 320 may alternatively include a motor configured to move the flood light source in small increments to form a generalized blurred light spot. In addition, the flood light source 320 may also generally include a light field patterning module such as a spatial light modulator for forming a patterned grayscale light field distribution. Since different grayscale values on the digital grayscale map represent different light intensities on the projected pattern, patterned flood exposure can be performed based on the grayscale map. In addition, the flood light source 320 and the laser light source included in the dual-beam or multi-beam laser interference lithography apparatus 310 may have the same or different wavelengths, as long as both are within the sensitive wavelength range of the photoresist. In an example, 405nm or 365nm can be selected as the wavelength of the flood light source.
控制器330可以实现为一个或多个处理模块。该一个或多个处理模块能够确定在经干涉曝光的晶片中的第一光场分布。在一个实施例中,所述确定第一光场分布可以包括:利用显影设备对经干涉曝光的样品进行显影;通过例如扫描电子显微镜的检测仪器对显影后的晶片的轮廓进行检测;并基于检测到的轮廓,确定在经干涉曝光的晶片中的第一光场分布。The controller 330 may be implemented as one or more processing modules. The one or more processing modules are capable of determining a first light field distribution in the interferometrically exposed wafer. In one embodiment, the determining the first light field distribution may include: using a developing device to develop the interference-exposed sample; detecting the profile of the developed wafer through a detection instrument such as a scanning electron microscope; and determining the first light field distribution in the interference-exposed wafer based on the detected profile.
在确定所述第一光场分布之后,所述控制器330还可以基于所确定的第一光场分布、预期的图案分布和泛光光源的参数,来确定泛光光源的光场分布,作为第二光场分布;并基于确定出的第二光场分布,对所述泛光光源的光场分布进行图案化,且控制具有经图案化的光场分布的泛光光源320对经干涉曝光的晶片进行图案化泛曝光,从而在经泛曝光的晶片中形成所述预期的图案分布。例如,如图2A至图2C所示,如果能够确定第一光场分布如图2B所示且预期的图案分布为具有图2A所示的均匀占空比的图案,那么在泛光光源与双光束或多光束激光干涉光刻设备所包括的激光光源具有相同波长的情况下,可以基于上述图案的差异来确定第二光场分布。在一个具体实施方式中,可以通过实验获取针对补偿值的经验性表格,并通过查表获得要得到目标占空比分布需要的泛曝光剂量分布。当然,在二者不具备相同波长的情况下,通过考虑该波长下的光对经干涉曝光的晶片内的第一光场分布的影响,来确定第二光场分布。更具体地,对于预期图案为具有均匀占空比的周期性图案的情况,在第一光场分布较小(即,干涉曝光剂量较小)的位置处施加较高的泛曝光剂量,且在第一光场分布较大(即,干涉曝光剂量较大)的位置处施加较低的泛曝光剂量,如图2C所示。After determining the first light field distribution, the controller 330 may also determine the light field distribution of the flood light source based on the determined first light field distribution, the expected pattern distribution, and the parameters of the flood light source as the second light field distribution; and based on the determined second light field distribution, pattern the light field distribution of the flood light source, and control the flood light source 320 having the patterned light field distribution to perform patterned flood exposure on the interference-exposed wafer, thereby forming the expected pattern distribution in the flood-exposed wafer. For example, as shown in FIGS. 2A to 2C , if it can be determined that the first light field distribution is as shown in FIG. 2B and the expected pattern distribution is a pattern with a uniform duty cycle as shown in FIG. 2A , then the second light field distribution can be determined based on the difference in the above-mentioned patterns when the flood light source and the laser light source included in the double-beam or multi-beam laser interference lithography apparatus have the same wavelength. In a specific implementation manner, an empirical table for the compensation value can be obtained through experiments, and the pan-exposure dose distribution required to obtain the target duty ratio distribution can be obtained through table lookup. Of course, in the case that the two do not have the same wavelength, the second light field distribution is determined by considering the effect of light at that wavelength on the first light field distribution in the interference exposed wafer. More specifically, for the case where the expected pattern is a periodic pattern with a uniform duty cycle, a higher flood exposure dose is applied at the position where the first light field distribution is small (i.e., the interference exposure dose is small), and a lower flood exposure dose is applied at the position where the first light field distribution is large (i.e., the interference exposure dose is large), as shown in FIG. 2C.
备选地,根据本公开示例实施例的激光干涉光刻设备还可以附加地包括显影单元,被配置为对经过泛曝光的晶片进行显影。Alternatively, the laser interference lithography apparatus according to example embodiments of the present disclosure may additionally include a developing unit configured to develop the flood-exposed wafer.
以上示出了根据本公开示例实施例的激光干涉光刻设备,该激光干涉光刻设备通过采用图案化泛曝光来补偿干涉曝光,即,根据干涉曝光后所得的第一光场分布来确定泛光光源的光场分布并基于此进行泛曝光补偿,可以实现任何给定的光刻图案等,即,能够可控地以较 高的精度提供期望的光刻图案,而不会显著增加设备的复杂程度和制造成本。所形成的干涉光刻图案可以是一维的光栅结构,也可以是二维的点阵、孔阵等结构。所形成的图案的应用包括分布反馈(DFB)激光器、场发射显示器(FED)、液晶显示器(LCD)、先进数据存储应用、光栅、度量标准和Moth-Eye亚波长结构(SWS)等。The above shows the laser interference lithography apparatus according to the exemplary embodiment of the present disclosure. The laser interference lithography apparatus compensates the interference exposure by adopting the patterned flood exposure, that is, the light field distribution of the flood light source is determined according to the first light field distribution obtained after the interference exposure and the flood exposure compensation is performed based thereon, so that any given lithography pattern can be realized, that is, the desired lithography pattern can be controllably provided with high precision without significantly increasing the complexity and manufacturing cost of the apparatus. The formed interference lithography pattern can be a one-dimensional grating structure, or a two-dimensional dot matrix, hole matrix and other structures. Applications for the patterned patterns include distributed feedback (DFB) lasers, field emission displays (FED), liquid crystal displays (LCD), advanced data storage applications, gratings, metrology, and Moth-Eye subwavelength structures (SWS), among others.
应注意,尽管以上描述以分立的形式阐述了根据本公开示例实施例的激光干涉光刻设备所包括的部件,然而上述部件可以分立地形成,也可以集成为一个系统。此外,上述部件也可以被拆分为多个部件,或相互组合为一个或多个部件而不影响本公开的实施。It should be noted that although the above description illustrates the components included in the laser interference lithography apparatus according to the exemplary embodiment of the present disclosure in a discrete form, the above components may be formed separately or integrated into one system. In addition, the above components may also be split into multiple components, or combined into one or more components without affecting the implementation of the present disclosure.
图4示出了根据本公开示例实施例的激光干涉光刻方法的流程图。根据本公开示例实施例的激光干涉光刻方法总体上可以包括:在操作S410,对涂覆有光刻胶的晶片执行干涉曝光;以及在操作S420,对经干涉曝光的晶片执行图案化泛曝光。在优选实施例中,在涂覆光刻胶之后,还可以附加地执行匀胶处理,以使所述光刻胶均匀涂覆。此外,所述激光干涉光刻方法还可以包括执行显影处理,即,对经泛曝光的晶片执行显影处理,从而最终能够提供期望的光刻图案。FIG. 4 shows a flowchart of a laser interference lithography method according to an example embodiment of the present disclosure. The laser interference lithography method according to example embodiments of the present disclosure may generally include: performing interference exposure on a photoresist-coated wafer in operation S410; and performing patterned flood exposure on the interference-exposed wafer in operation S420. In a preferred embodiment, after the photoresist is coated, a leveling treatment may be additionally performed to make the photoresist evenly coated. In addition, the laser interference lithography method may further include performing a developing process, that is, performing a developing process on the flood-exposed wafer, so that a desired photolithographic pattern can finally be provided.
图5示出了根据本公开示例实施例的泛曝光工艺的流程图。具体地,执行泛曝光的操作S420可以进一步包括操作S421至S423。FIG. 5 shows a flowchart of a flood exposure process according to an example embodiment of the present disclosure. Specifically, operation S420 of performing the flood exposure may further include operations S421 to S423.
在操作S421,确定在所述经干涉曝光的晶片中的第一光场分布。如上所述,确定第一光场分布可以包括:利用显影设备对经干涉曝光的样品进行显影;通过例如扫描电子显微镜的检测仪器对显影后的晶片的轮廓进行检测;并基于检测到的轮廓,确定在经干涉曝光的晶片中的第一光场分布。In operation S421, a first light field distribution in the interference-exposed wafer is determined. As described above, determining the first light field distribution may include: developing the interference-exposed sample using a developing device; detecting a profile of the developed wafer by a detection instrument such as a scanning electron microscope; and determining the first light field distribution in the interference-exposed wafer based on the detected profile.
在操作S422,基于所述第一光场分布、预期的图案分布和用于所述泛曝光的泛光光源的参数,确定所述泛光光源的光场分布,作为第二光场分布。对于预期图案分布是具有均匀占空比的周期性图案的情况,确定第二光场分布包括在第一光场分布较小(即,干涉曝光剂量较小)的位置处施加较高的泛曝光剂量,且在第一光场分布较大(即,干涉曝光剂量较大)的位置处施加较低的泛曝光剂量。然而,对于预期图案分布是具有空间调制的占空比的图案分布,可以确定所述第二 光场分布,使得经泛曝光的晶片中形成所述具有空间调制的占空比的图案分布。In operation S422, a light field distribution of the flood light source is determined as a second light field distribution based on the first light field distribution, the expected pattern distribution and parameters of the flood light source used for the flood exposure. For the case where the expected pattern distribution is a periodic pattern with a uniform duty cycle, determining the second light field distribution includes applying a higher flood exposure dose at locations where the first light field distribution is small (i.e., the interference exposure dose is small) and applying a lower flood exposure dose at locations where the first light field distribution is large (i.e., the interference exposure dose is large). However, for the expected pattern distribution to be a pattern distribution with a spatially modulated duty cycle, said second optical field distribution may be determined such that said pattern distribution with a spatially modulated duty cycle is formed in the flood exposed wafer.
在操作S423,基于所述第二光场分布,对所述泛光光源的光场分布进行图案化,并控制具有经图案化的光场分布的所述泛光光源对经干涉曝光的晶片进行图案化泛曝光,从而在经泛曝光的晶片中形成所述预期的图案分布。例如,当所述泛光光源中配置有例如空间光调制器的光场图案化模块时,可以通过经由所述光场图案化模块对所述泛光光源的光场分布进行图案化,以具有所述第二光场分布。In operation S423, pattern the light field distribution of the flood light source based on the second light field distribution, and control the flood light source with the patterned light field distribution to perform patterned flood exposure on the interference-exposed wafer, thereby forming the expected pattern distribution in the flood-exposed wafer. For example, when a light field patterning module such as a spatial light modulator is configured in the flood light source, the light field distribution of the flood light source may be patterned through the light field patterning module to have the second light field distribution.
可见,根据本公开示例实施例的激光干涉光刻方法通过采用泛曝光来补偿干涉曝光,即,根据干涉曝光后所得的第一光场分布确定泛光光源的光场分布并基于此进行泛曝光补偿,可以实现任何给定的光刻图案等,即,能够可控地以较高的精度提供期望的光刻图案,而不会显著增加设备的复杂程度和制造成本。通过采用根据本公开示例实施例所示的设备和方法形成的干涉光刻图案可以是一维的光栅结构,也可以是二维的点阵、孔阵等结构。所形成的图案的应用包括分布反馈(DFB)激光器、场发射显示器(FED)、液晶显示器(LCD)、先进数据存储应用、光栅、度量标准和Moth-Eye亚波长结构(SWS)等。It can be seen that the laser interference lithography method according to the exemplary embodiment of the present disclosure compensates the interference exposure by using flood exposure, that is, determines the light field distribution of the flood light source according to the first light field distribution obtained after the interference exposure and performs flood exposure compensation based on it, can realize any given photolithography pattern, that is, can provide the desired photolithography pattern with high precision in a controllable manner without significantly increasing the complexity of the equipment and the manufacturing cost. The interference lithography pattern formed by using the apparatus and method shown in the exemplary embodiments of the present disclosure may be a one-dimensional grating structure, or a two-dimensional dot matrix, hole matrix and other structures. Applications for the patterned patterns include distributed feedback (DFB) lasers, field emission displays (FED), liquid crystal displays (LCD), advanced data storage applications, gratings, metrology, and Moth-Eye subwavelength structures (SWS), among others.
图6至图11分别示出了应用根据本公开示例实施例所述的方法和装置的示例。6 to 11 illustrate examples of applying the method and apparatus according to example embodiments of the present disclosure, respectively.
图6示出了利用本公开示例实施例的激光干涉光刻设备和方法形成的周期例如为1μm的栅状结构。在对相同周期的结构的实验研究中,如图6中的a图所示,将干涉图案的曝光剂量以4.6mJ/cm 2的步长从27.6mJ/cm 2逐渐增加到55.2mJ/cm 2,并将泛光光源的曝光剂量从0mJ/cm 2逐步增加到13.2mJ/cm 2,在不同的干涉曝光剂量和泛光曝光剂量下观察栅状结构的电镜图像,可以发现:增加干涉曝光剂量和/或泛光曝光剂量会缩小线宽。然而,在不同的初始干涉曝光剂量下,会具有不同的线宽调制范围,其中较低的初始干涉曝光剂量会导致较大的线宽调制范围,如图6中的b图所示。例如,泛光光源的曝光剂量从0mJ/cm 2逐步增加到13.2mJ/cm 2能够使最初以27.6mJ/cm 2曝光的栅状结构产生约180nm的线宽变化,而仅能使最初以55.2mJ/cm 2 曝光的栅状结构产生约140nm的线宽变化。 FIG. 6 shows a grid-like structure with a period of, for example, 1 μm formed using the laser interference lithography apparatus and method of an exemplary embodiment of the present disclosure. In the experimental study on structures with the same period, as shown in Figure 6a, the exposure dose of the interference pattern was gradually increased from 27.6mJ/cm 2 to 55.2mJ/cm 2 with a step length of 4.6mJ/cm 2 , and the exposure dose of the flood light source was gradually increased from 0mJ/cm 2 to 13.2mJ/cm 2 . and/or flood exposure dose will narrow the linewidth. However, under different initial interference exposure doses, there will be different linewidth modulation ranges, and a lower initial interference exposure dose will result in a larger linewidth modulation range, as shown in Figure 6b. For example, gradually increasing the exposure dose of the flood light source from 0mJ/ cm2 to 13.2mJ/ cm2 can produce a linewidth change of about 180nm for the grid-like structure initially exposed at 27.6mJ/ cm2 , but only about 140nm for the grid-like structure initially exposed at 55.2mJ/ cm2 .
图7和图8示出了采用理想干涉图案的双光束或多光束激光干涉光刻设备和具有图案化分布的泛光光源执行二次曝光的示意图。7 and 8 show schematic diagrams of double-beam or multi-beam laser interference lithography apparatus using ideal interference patterns and a flood light source with patterned distribution to perform secondary exposure.
图7示出了利用根据本公开示例实施例的激光干涉光刻设备和方法在3英寸样品上制造具有空间调制的占空比的图案的样品图,和该3英寸样品上的分别对应于背景、字母“H”、字母“K”和字母“U”的位置处的电镜扫描图。该晶片上的栅状结构的周期同为600nm,但存在四种线宽。具体地,位于背景中栅状结构的线宽为250nm,位于字母“H”处栅状结构的线宽为190nm,位于字母“K”处栅状结构的线宽为140nm,且位于字母“U”处栅状结构的线宽为110nm。7 shows a sample image of a pattern with a spatially modulated duty cycle fabricated on a 3-inch sample using a laser interference lithography apparatus and method according to an exemplary embodiment of the present disclosure, and scanning electron microscope images of positions corresponding to the background, the letter "H", the letter "K" and the letter "U" on the 3-inch sample, respectively. The period of the grid structure on the wafer is also 600nm, but there are four kinds of line widths. Specifically, the line width of the grid structure located in the background is 250nm, the line width of the grid structure located at the letter "H" is 190nm, the line width of the grid structure located at the letter "K" is 140nm, and the line width of the grid structure located at the letter "U" is 110nm.
图8示出了使用根据本公开示例实施例所述的方法和装置在大尺寸晶片上获得具有均匀线宽的栅状结构的示例。当用具有理想干涉图案的双光束或多光束激光干涉光刻设备对大尺寸晶片进行加工时,由于晶片尺寸较大或干涉光源性能等各方面原因,导致干涉图案在晶片上的分布可能偏离理想干涉图案。因此,可能导致由此产生的栅状结构具有不均匀的线宽。基于本申请的构思,在这种情况下,可以利用图案化的泛光光源执行二次曝光,以进行补偿。FIG. 8 shows an example of obtaining a grid-like structure with a uniform line width on a large-sized wafer using the method and apparatus according to example embodiments of the present disclosure. When processing a large-sized wafer with a double-beam or multi-beam laser interference lithography device with an ideal interference pattern, the distribution of the interference pattern on the wafer may deviate from the ideal interference pattern due to various reasons such as the large size of the wafer or the performance of the interference light source. Therefore, the resulting grid-like structure may have non-uniform line widths. Based on the concept of the present application, in this case, a second exposure can be performed using a patterned flood light source to compensate.
例如,图8中的a图示出了仅使用干涉全息方法来对大尺寸晶片(例如,4英寸)执行光刻的示意图,其电镜扫描图((a1)图至(a4)图)充分展示了所制造的栅状结构的宽度从127nm加宽至270nm。相对地,b图示出了使用根据本公开示例实施例的光刻方法对大尺寸晶片执行光刻的示意图,其电镜扫描图((b1)图至(b4)图)充分展示了所制造的栅状结构的宽度基本保持在127nm。c图和d图分别示出了在4英寸晶片上的栅状结构的线宽和线宽粗糙度随位置的变化。For example, Figure a in Figure 8 shows a schematic diagram of performing photolithography on a large-scale wafer (for example, 4 inches) using only the interference holography method, and its scanning electron microscope images (Figures (a1) to Figures (a4)) fully demonstrate that the width of the fabricated grid structure is widened from 127nm to 270nm. In contrast, Figure b shows a schematic diagram of performing photolithography on a large-scale wafer using a photolithography method according to an exemplary embodiment of the present disclosure, and its scanning electron microscope images (Figures (b1) to Figures (b4)) fully demonstrate that the width of the fabricated grid structure is substantially maintained at 127nm. Panels c and d show the line width and line width roughness of the grid-like structure on a 4-inch wafer as a function of position, respectively.
由此能够看出,通过使用根据本公开示例实施例的光刻方法,能够将栅状结构的线宽偏差从36.2nm减小至3.2nm。此外,线宽粗糙度也得到了显着改善,尤其是对于晶片边缘附近的栅状结构。It can be seen from this that, by using the photolithography method according to the exemplary embodiment of the present disclosure, the line width deviation of the grid structure can be reduced from 36.2 nm to 3.2 nm. In addition, the line width roughness has also been significantly improved, especially for grid-like structures near the wafer edge.
除了图案化大面积且均匀分布的栅状结构之外,本公开示例实施例的激光干涉光刻设备和方法还可以对二维纳米结构的填充率进行空间调制。In addition to patterning large-area and uniformly distributed grid-like structures, the laser interference lithography apparatus and method of example embodiments of the present disclosure can also spatially modulate the filling rate of two-dimensional nanostructures.
图9示出了通过使用根据本公开示例实施例的方法和装置来对二维纳米结构的填充率进行空间调制的示例。在氧化硅晶片的背面上曝光700nm周期的二维图案,然后使用由25个灰度值组成的灰度图来调节填充率,其中25个灰度值代表不同曝光剂量。a图示出了显影基板的照片和标记区域的电镜图像,其中当用于二次曝光的灰度值从0增加到240时,5×5单元中颜色逐渐从棕色变为金色,该基板包括700nm周期的二维纳米结构,且具有通过灰度图案二次曝光调节的各种填充率。b图示出了a图中的25个区域的光刻胶填充率。由b图可以看出,光刻胶填充率随着用于二次曝光的剂量的增加而下降。c图示出了在3英寸晶片上制造精细画作的示意。可见,根据本公开示例实施例的设备和方法能够对二维纳米结构的填充率进行有效空间调制。FIG. 9 shows an example of spatially modulating the fill rate of a two-dimensional nanostructure by using the method and apparatus according to example embodiments of the present disclosure. A two-dimensional pattern with a period of 700nm is exposed on the backside of a silicon oxide wafer, and then the filling rate is adjusted using a grayscale map consisting of 25 grayscale values representing different exposure doses. a shows a photograph of a developed substrate comprising 2D nanostructures with a period of 700 nm and an electron microscope image of a marked area, in which the color gradually changes from brown to gold in a 5 × 5 cell as the gray value for the secondary exposure increases from 0 to 240, with various fill rates tuned by the secondary exposure of the grayscale pattern. Panel b shows the photoresist fill ratio for the 25 regions in panel a. It can be seen from Figure b that the photoresist fill rate decreases as the dose used for secondary exposure increases. Figure c shows a schematic of the fabrication of fine paintings on a 3-inch wafer. It can be seen that the devices and methods according to example embodiments of the present disclosure can effectively spatially modulate the filling rate of two-dimensional nanostructures.
从图7至图9可以看出,可以将根据本公开示例实施例的激光干涉光刻设备和方法应用于制造具有空间调制的占空比的图案,突破了激光干涉光刻设备和方法的应用限制。据此,可以对现有的干涉光刻系统进行改进,从而用于在较大的面积上产生具有周期性或不具有周期性的期望纳米结构。It can be seen from FIGS. 7 to 9 that the laser interference lithography apparatus and method according to example embodiments of the present disclosure can be applied to fabricate patterns with spatially modulated duty cycles, breaking through the application limitations of the laser interference lithography apparatus and method. Accordingly, existing interference lithography systems can be modified for producing desired nanostructures with or without periodicity over larger areas.
此外,还应注意,尽管本申请以执行干涉曝光后执行图案化泛曝光的顺序描述了本发明构思,但是,本领域技术人员应清楚。执行干涉曝光和执行图案化曝光的顺序可以是相反的,即,可以在执行泛曝光之后再执行干涉曝光。此外,二者也可以是基本同时执行的。附图中的流程图和框图,图示了按照本公开各种实施例的系统、方法和计算机程序产品的可能实现的体系架构、功能和操作。在这点上,流程图或框图中的每个方框可以代表一个模块、程序段、或代码的一部分,上述模块、程序段、或代码的一部分包含一个或多个用于实现规定的逻辑功能的可执行指令。也应当注意,在有些作为替换的实现中,方框中所标注的功能也可以以不同于附图中所标注的顺序发生。例如,两个接连表示的方框实际上可以基本并行地执行,它们有时也可以按相反的顺序执行,这依所涉及的功能而定。也要注意的是,框图或流程图中的每个方框、以及框图或流程图中的方框的组合,可以用执行规定的功能或操作的专用的基于硬件的系统来实现,或者可以用专用 硬件与计算机指令的组合来实现。In addition, it should also be noted that although the present application describes the inventive concept in the order of performing interference exposure followed by patterning flood exposure, it should be clear to those skilled in the art. The order of performing interference exposure and patterning exposure may be reversed, that is, interference exposure may be performed after flood exposure is performed. In addition, both may also be performed substantially simultaneously. The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, program segment, or a portion of code that includes one or more executable instructions for implementing specified logical functions. It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or they may sometimes be executed in the reverse order, depending upon the functionality involved. It should also be noted that each block in the block diagrams or flowchart illustrations, and combinations of blocks in the block diagrams or flowchart illustrations, can be implemented by special purpose hardware-based systems that perform the specified functions or operations, or by combinations of special purpose hardware and computer instructions.
本领域技术人员可以理解,尽管已经参照本公开的特定示例性实施例示出并描述了本公开,但是本领域技术人员应该理解,在不背离所附权利要求及其等同物限定的本公开的精神和范围的情况下,可以对本公开进行形式和细节上的多种改变。因此,本公开的范围不应该限于上述实施例,而是应该不仅由所附权利要求来进行确定,还由所附权利要求的等同物来进行限定。It will be understood by those skilled in the art that, while the present disclosure has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made in the present disclosure without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above-described embodiments, but should be determined not only by the appended claims, but also by the equivalents of the appended claims.
Claims (16)
- A laser interference lithography apparatus comprising:a dual beam or multi beam laser interference lithography apparatus configured to perform interference exposure on a photoresist coated wafer;a flood light source having a light field distribution that can be patterned and configured to pattern flood exposure of the interference exposed wafer; anda controller configured to:determining a first light field distribution in the interference-exposed wafer;determining a light field distribution of the floodlight source as a second light field distribution based on the first light field distribution, an expected pattern distribution, and parameters of the floodlight source; andpatterning a light field distribution of the flood light source based on the second light field distribution and controlling the flood light source having the patterned light field distribution to pattern flood exposure of an interference exposed wafer to form the desired pattern distribution in the flood exposed wafer.
- The laser interference lithography apparatus of claim 1, wherein the flood light source further comprises a defocus module configured to defocus light emitted by the flood light source to form a blurred spot that is generalized.
- The laser interference lithography apparatus of claim 1, wherein the flood light source further comprises a motor configured to move the flood light source a small amount to form a generalized blurred spot.
- The laser interference lithography apparatus of claim 1, wherein the flood light source further comprises a light field patterning module, andwherein the controller is further configured to pattern a light field distribution of the floodlight source via the light field patterning module to have the second light field distribution.
- The laser interference lithography apparatus of claim 1, further comprising a developing unit configured to develop the flood exposed wafer.
- The laser interference lithography apparatus of claim 1, wherein the patterned flood light source is implemented using a gray scale map from a UV projector, wherein different gray scale values in the gray scale map represent different light intensities.
- The laser interference lithography apparatus of claim 1, wherein the first light field distribution is an ideal interference pattern and the second light field distribution is a uniform distribution.
- The laser interference lithography apparatus of claim 1, wherein the first light field distribution is an ideal interference pattern and the second light field distribution is a stepped distribution.
- A laser interference lithography method, comprising:performing interference exposure on the photoresist-coated wafer; anda patterned flood exposure is performed on the interference exposed wafer,wherein performing the patterned flood exposure comprises:determining a first light field distribution in the interference exposed wafer;determining a light field distribution of the flood light source as a second light field distribution based on the first light field distribution, an expected pattern distribution, and parameters of the flood light source for the patterned flood exposure; andpatterning a light field distribution of the flood light source based on the second light field distribution and controlling the flood light source having the patterned light field distribution to pattern flood exposure of an interference exposed wafer to form the desired pattern distribution in the flood exposed wafer.
- The laser interference lithography method of claim 9, further comprising: a developing process is performed on the flood exposed wafer.
- The laser interference lithography method of claim 9, determining the first light field distribution comprising:developing the interference-exposed sample;detecting the outline of the developed wafer by a scanning electron microscope; andbased on the detected profile, the first light field distribution in the interferometrically exposed wafer is determined.
- The laser interference lithography method of claim 9, wherein determining the second light field distribution comprises: in response to determining that the expected pattern distribution is a periodic pattern with a uniform duty cycle, it is determined to apply a higher flood exposure dose at locations where the first light field distribution is smaller and a lower flood exposure dose at locations where the first light field distribution is larger.
- The laser interference lithography method of claim 9, wherein determining the second light field distribution comprises: in response to determining that the expected pattern distribution is a pattern distribution having a spatially modulated duty cycle, the second light field distribution is determined such that the pattern distribution having a spatially modulated duty cycle is formed in the flood exposed wafer.
- The laser interference lithography method of claim 9, wherein the patterned flood light source is implemented using a gray scale map from a UV projector, wherein different gray scale values in the gray scale map represent different light intensities.
- The laser interference lithography method of claim 9, wherein the first light field distribution is an ideal interference pattern and the second light field distribution is a uniform distribution.
- The laser interference lithography method of claim 9, wherein the first light field distribution is an ideal interference pattern and the second light field distribution is a stepped distribution.
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US8568964B2 (en) * | 2009-04-27 | 2013-10-29 | Tokyo Electron Limited | Flood exposure process for dual tone development in lithographic applications |
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